Neurophysiological Monitoring of Cranial Nerves During Posterior Fossa Surgery

1995 ◽  
pp. 35-39 ◽  
Author(s):  
Giovanni Broggi ◽  
V. Scaioli ◽  
S. Brock ◽  
I. Dones
Keyword(s):  
Posterior Fossa ◽  
Cranial Nerves ◽  
Neurophysiological Monitoring ◽  
Posterior Fossa Surgery

Posterior Fossa

2019 ◽  
Author(s):  
Talia S. Vogel ◽  
Penny P. Liu
Keyword(s):  
Posterior Fossa ◽  
Preoperative Evaluation ◽  
Cranial Nerves ◽  
Air Embolism ◽  
Neurophysiological Monitoring ◽  
Posterior Fossa Surgery ◽  
Neurophysiologic Monitoring ◽  
Venous Air Embolism ◽  
Brainstem Stroke ◽  
Air Embolus

The posterior fossa houses essential brainstem nuclei, cranial nerves, cerebral vasculature, and mechanisms for cerebrospinal fluid drainage. Anesthetic considerations for posterior fossa surgery include thorough preoperative evaluation, intraoperative monitoring, and anesthetic planning to allow neurophysiological monitoring. Careful positioning is imperative to optimize surgical conditions and to risk stratify patients for complications, including venous air embolus. Venous air embolus is a common complication of posterior fossa surgery given the plentitude of venous channels in the posterior fossa, and rapid recognition is key to managing this complication.  Posterior fossa surgery also has a number of other known complications including postoperative apnea, prolonged ventilation, and possible brainstem stroke.  This review contains 4 tables, 1 video, and 31 references. Keywords: Posterior fossa surgery, Brainstem surgery, Neuroanesthesiology, Venous air embolism/embolus, Sitting craniotomy, Prone craniotomy, Transesophageal echocardiogram, Neurophysiologic monitoring

scholarly journals NS-01PEDIATRIC INTRAOPERATIVE NEUROPHYSIOLOGICAL MONITORING IN POSTERIOR FOSSA SURGERY

2016 ◽  
Vol 18 (suppl 3) ◽  
pp. iii127.1-iii127
Author(s):  
Franco Randi ◽  
Andrea Carai ◽  
Gionatan Amante ◽  
Alessandro De Benedictis ◽  
Raffaella Messina ◽  
...  
Keyword(s):  
Posterior Fossa ◽  
Intraoperative Neurophysiological Monitoring ◽  
Neurophysiological Monitoring ◽  
Posterior Fossa Surgery

scholarly journals Intraoperative neurophysiological monitoring during resection of infratentorial lesions: the surgeon's view

2017 ◽  
Vol 126 (1) ◽  
pp. 281-288 ◽  
Author(s):  
Philipp J. Slotty ◽  
Amr Abdulazim ◽  
Kunihiko Kodama ◽  
Mani Javadi ◽  
Daniel Hänggi ◽  
...  
Keyword(s):  
Evoked Potentials ◽  
Posterior Fossa ◽  
Auditory Evoked Potentials ◽  
Motor Evoked Potentials ◽  
Neurological Deficits ◽  
Neurophysiological Monitoring ◽  
Posterior Fossa Surgery ◽  
Lesion Location ◽  
Crucial Information ◽  
Free Running

OBJECTIVE Methods of choice for neurophysiological intraoperative monitoring (IOM) within the infratentorial compartment mostly include early brainstem auditory evoked potentials, free-running electromyography, and direct cranial nerve (CN) stimulation. Long-tract monitoring with somatosensory evoked potentials (SEPs) and motor evoked potentials (MEPs) is rarely used. This study investigated the incidence of IOM alterations during posterior fossa surgery stratified for lesion location. METHODS Standardized CN and SEP/MEP IOM was performed in 305 patients being treated for various posterior fossa pathologies. The IOM data were correlated with lesion locations and histopathological types as well as other possible confounding factors. RESULTS Alterations in IOM were observed in 158 of 305 cases (51.8%) (CN IOM alterations in 130 of 305 [42.6%], SEP/MEP IOM alterations in 43 of 305 [14.0%]). In 15 cases (4.9%), simultaneous changes in long tracts and CNs were observed. The IOM alterations were followed by neurological sequelae in 98 of 305 cases (32.1%); 62% of IOM alterations resulted in neurological deficits. Sensitivity and specificity for detection of CN deficits were 98% and 77%, respectively, and 95% and 85%, respectively, for long-tract deficits. Regarding location, brainstem and petroclival lesions were closely associated with concurrent CN IOM and SEP/MEP alterations. CONCLUSIONS The incidence of IOM alterations during surgery in the posterior fossa varied widely between different lesion locations and histopathological types. This analysis provides crucial information on the necessity of IOM in different surgical settings. Because MEP/SEP and CN IOM alterations were commonly observed during posterior fossa surgery, the authors recommend the simultaneous use of both modalities based on lesion location.

scholarly journals Feasibility of cerebello-cortical stimulation for intraoperative neurophysiological monitoring of cerebellar mutism

2021 ◽  
Author(s):  
Davide Giampiccolo ◽  
Federica Basaldella ◽  
Andrea Badari ◽  
Giovanna Maddalena Squintani ◽  
Luigi Cattaneo ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Test Stimulus ◽  
Posterior Fossa ◽  
Motor Evoked Potentials ◽  
Significant Inhibition ◽  
Neurophysiological Monitoring ◽  
Posterior Fossa Surgery ◽  
Cerebellar Mutism ◽  
Motor Cortex Excitability ◽  
Electrical Conditioning

Abstract Background Cerebellar mutism can occur in a third of children undergoing cerebellar resections. Recent evidence proposes it may arise from uni- or bilateral damage of cerebellar efferents to the cortex along the cerebello-dento-thalamo-cortical pathway. At present, no neurophysiological procedure is available to monitor this pathway intraoperatively. Here, we specifically aimed at filling this gap. Methods We assessed 10 patients undergoing posterior fossa surgery using a conditioning-test stimulus paradigm. Electrical conditioning stimuli (cStim) were delivered to the exposed cerebellar cortex at interstimulus intervals (ISIs) of 8–24 ms prior to transcranial electric stimulation of the motor cortex, which served as test stimulus (tStim). The variation of motor-evoked potentials (MEP) to cStim + tStim compared with tStim alone was taken as a measure of cerebello-cortical connectivity. Results cStim alone did not produce any MEP. cStim preceding tStim produced a significant inhibition at 8 ms (p < 0.0001) compared with other ISIs when applied to the lobules IV-V-VI in the anterior cerebellum and the lobule VIIB in the posterior cerebellum. Mixed effects of decrease and increase in MEP amplitude were observed in these areas for longer ISIs. Conclusions The inhibition exerted by cStim at 8 ms on the motor cortex excitability is likely to be the product of activity along the cerebello-dento-thalamo-cortical pathway. We show that monitoring efferent cerebellar pathways to the motor cortex is feasible in intraoperative settings. This study has promising implications for pediatric posterior fossa surgery with the aim to preserve the cerebello-cortical pathways and thus prevent cerebellar mutism.

Mutism after posterior fossa surgery in children

1990 ◽  
Vol 72 (6) ◽  
pp. 959-963 ◽  
Author(s):  
Luigi Ferrante ◽  
Luciano Mastronardi ◽  
Michele Acqui ◽  
Aldo Fortuna
Keyword(s):  
Posterior Fossa ◽  
Fourth Ventricle ◽  
Cranial Nerves ◽  
Speech Disorder ◽  
Posterior Fossa Surgery ◽  
Content Type ◽  
Disturbance Of Consciousness ◽  
Lower Cranial Nerves ◽  
Fine Print

✓ Three patients aged 5½ to 9 years old with mutism after posterior fossa surgery are presented. The entity is discussed with a review of 15 additional previously reported cases in children aged 2 to 11 years. In all 18 patients, a large midline tumor of the posterior fossa (medulloblastoma in nine cases, astrocytoma in five, and ependymoma in four), often attached to one or both lateral recesses of the fourth ventricle, was removed. Mutism developed 18 to 72 hours after the operation (mean 41.5 hours) in patients with no disturbance of consciousness and no deficits of the lower cranial nerves or of the organs of phonation. All of these children had spoken in the first hours after surgery. The disorder lasted from 3 to 16 weeks (mean 7.9 weeks). Speech was regained after a period of dysarthria in six of the 10 cases for whom this information was available. The various hypotheses advanced to explain the pathogenesis of this speech disorder are analyzed.

Adjunctive Use of Endoscopy during Posterior Fossa Surgery to Treat Cranial Neuropathies

Neurosurgery ◽  
2001 ◽  
Vol 49 (1) ◽  
pp. 108-116 ◽  
Author(s):  
Wesley A. King ◽  
Phillip A. Wackym ◽  
Chandranath Sen ◽  
Glenn A. Meyer ◽  
John Shiau ◽  
...  
Keyword(s):  
Posterior Fossa ◽  
Microvascular Decompression ◽  
Cranial Nerves ◽  
Internal Auditory Canal ◽  
Vascular Compression ◽  
Posterior Fossa Surgery ◽  
Suboccipital Craniotomy ◽  
Neoplastic Processes ◽  
Rigid Endoscope ◽  
Cranial Neuropathies

Abstract OBJECTIVE The objective of this study was to determine the utility and safety of rigid endoscopy as an adjunct during posterior fossa surgery to treat cranial neuropathies. METHODS A suboccipital craniotomy was performed for 19 patients with non-neoplastic processes involving the Vth, VIIth, and/or VIIIth cranial nerves. Ten patients with trigeminal neuralgia (n = 8), hemifacial spasm (n = 1), or intractable tinnitus (n = 1) underwent primarily microvascular decompression procedures. One patient with geniculate neuralgia underwent nervus intermedius sectioning combined with microvascular decompression. Eight patients underwent unilateral vestibular nerve neurectomies for treatment of Ménière's disease. A 0- or 30-degree rigid endoscope was used in conjunction with the standard microscopic approach for all procedures. RESULTS All patients experienced resolution or significant improvement of their preoperative symptoms after posterior fossa surgery. The endoscope allowed improved definition of anatomic neurovascular relationships without the need for significant cerebellar or brainstem retraction. Cleavage planes between the cochlear and vestibular nerves entering the internal auditory canal and sites of vascular compression could not be microscopically observed for several patients; however, endoscopic identification was possible for all patients. There were no complications related to the use of the endoscope. CONCLUSION The rigid endoscope can be used safely during posterior fossa surgery to treat cranial neuropathies, and it allows improved observation of the cranial nerves, nerve cleavage planes, and vascular anatomic features without significant cerebellar or brainstem retraction.

scholarly journals Comparison of Diffusion-Weighted MRI Reconstruction Methods for Visualization of Cranial Nerves in Posterior Fossa Surgery

2017 ◽  
Vol 11 ◽  
Author(s):  
Brendan Behan ◽  
David Q. Chen ◽  
Francesco Sammartino ◽  
Danielle D. DeSouza ◽  
Erika Wharton-Shukster ◽  
...  
Keyword(s):  
Posterior Fossa ◽  
Cranial Nerves ◽  
Posterior Fossa Surgery ◽  
Diffusion Weighted Mri ◽  
Diffusion Weighted ◽  
Reconstruction Methods ◽  
Mri Reconstruction

scholarly journals Electrophysiological Monitoring During Acoustic Neuroma and Other Posterior Fossa Surgery

1988 ◽  
Vol 15 (1) ◽  
pp. 73-81 ◽  
Author(s):  
R.D. Linden ◽  
C.H. Tator ◽  
C. Benedict ◽  
D. Charles ◽  
V. Mraz ◽  
...  
Keyword(s):  
Facial Nerve ◽  
Real Time ◽  
Posterior Fossa ◽  
Acoustic Neuroma ◽  
Auditory Nerve ◽  
Cranial Nerves ◽  
Intracranial Stimulation ◽  
Electromyographic Activity ◽  
Posterior Fossa Surgery ◽  
Brainstem Response

ABSTRACT:Techniques used to monitor the function of the seventh and eighth cranial nerves during acoustic neuroma and other posterior fossa surgery are reviewed. The auditory brainstem response (ABR), electrocochleogram (ECochG) and direct recording from the auditory nerve (CNAP) were compared. The best technique is the ECochG, although in many cases, the CNAP should be used as a back-up technique. The CNAP is especially useful for the identification of the auditory nerve. Both can provide real-time feedback on the physiological integrity of the auditory nerve. The ABR may be helpful in monitoring brainstem function. For some procedures, optimal monitoring requires the combined recording of all three techniques.Monopolar constant-voltage intracranial stimulation of the facial nerve is helpful for the identification and preservation of the facial nerve. Audio monitoring of spontaneous electromyographic activity provides real-time feedback on the effect of surgical manipulation of the nerve. Monitoring of ephaptic transmission in the facial nerve during microvascular decompression for hemifacial spasm aids in the identification of the offending vessel.

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